1. Field of the Invention
The present invention relates to a ball screw device, and more particularly to a ball screw device having a radially inserted and secured deflecting member for effectively and smoothly receiving and guiding the balls or the bearing members to move relative to the ball nut and the screw shaft, and for facilitating the rotational movement of the ball nut and the screw shaft relative to each other in great rotational speeds.
2. Description of the Prior Art
Typical ball screw devices comprise a ball nut rotatably and/or moveably engaged onto a screw shaft, and normally arranged to allow the ball nut to be rotated and/or moved relative to the screw shaft in great rotational speeds. For allowing the ball nut to be smoothly rotated and moved relative to the screw shaft, a suitable bearing device or lubricating structure is further required to be provided and engaged between the ball nut and the screw shaft, for facilitating the rotational movement between the ball nut and the screw shaft.
For example, U.S. Pat. No. 4,357,838 to Blaurock et al. discloses one of the typical ball screw devices including a deflecting member provided or engaged into the ball nut for forming a ball return passage or an endless ball train guiding passage and for receiving a number of balls or a ball train therein, and for allowing the balls or the ball train to be engaged between the ball nut and the screw shaft to facilitate the rotational movement between the ball nut and the screw shaft.
In Blaurock et al., the deflecting member includes a prismatic recess formed into an inner surface of a nut body and extends axially inwardly from an end face of the nut body. However, the prismatic recess may not be used to receive and to guide the balls or ball train into any inner and radially extended channels in the nut body, such that the balls or the ball train may not be effectively guided to move into the corresponding axial return passages of the ball nut.
U.S. Pat. No. 6,425,302 to Greubel discloses another typical ball screw device including two deflecting members attached to or engaged into the ball nut and having a curved deflecting passage formed therein for guiding or deflecting the balls or the ball train, and two fastening pins are required to secure each of the deflecting members to the ball nut.
However, the fastening pins may only be used to anchor the deflecting members to the ball nut, but may not solidly secure and position the deflecting members to the ball nut. For allowing the deflecting members to be solidly secured and positioned the ball nut, the cutouts for receiving the deflecting members and the blind bores for receiving the fastening pins are required to be precisely machined and formed in the ball nut, otherwise, the deflecting members may be loosened relative to the ball nut and may not be used to suitably guide the balls or ball train through the endless ball train guiding passage of the ball nut.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional ball screw devices for such as machine tools or the like.